#include <stdio.h>

int main(int argc, char const *argv[])
{
    int a[] = {0,1,2,3,4,5,6,7};
    int n = sizeof(a)/sizeof(a[0]); //元素个数
    printf("%d\n", n);  
    int i = 0;
    int j = n-1;
    int tmp;
    while(i<j){
    	tmp = a[i];
    	a[i] = a[j];
    	a[j] = tmp;
    	i++;
    	j--;
    }

    for (int i = 0; i < n; i++)
    {
    	printf("%d\n", a[i]);
    }

    return 0;
}
